Fluoride Action Network

Abstract

Fluorosis causes female reproductive dysfunction with reduced fertility without established pathogenesis. To clarify the mechanism, Sprague–Dawley female rats were selected with drinking water containing 0, 50 (low), 100 (moderate), and 150 mg/L (high) sodium fluoride (NaF) for a short (2 months), medium (4 months), and long term (6 months). The water consumption and body weight of female rats were recorded daily. The effect of NaF on the estrous cycle was examined by vaginal smears and recorded in different term treatments. Female and male rats were mated in a 2:1 ratio for 1 week at 2-, 4-, and 6-month treatment time for mating performance and fertility rate. Selected female rats were executed for tissue and blood collection at different treatment terms. Twenty-four-hour urine sample from each female rat was collected using the metabolic cage. The levels of steroid hormones and silent information regulator 2 homolog 1 (SIRT1) in serum were measured by appropriate ELISA kits. Body weight of the high NaF group was significantly less during short-term treatment than that of other treatment groups or control group. Urinary fluoride concentration was increased linearly with treatment time. Treatment of NaF significantly decreased steroid hormone level while increased SIRT1 level in the serum. In addition, NaF treatment significantly decreased pregnancy rate. It is concluded that NaF inhibits the secretion of hormone and estradiol (E2) release from the ovary, thereby reducing the rate of pregnant. SIRT1 may be involved in this NaF-induced reproductive dysfunction in female rats through regulating reproductive hormone, FSH, and LH secretion.

Data Availability

The data underlying this article are available in the article and in its online supplementary material.


*Original abstract online at https://link.springer.com/article/10.1007/s12011-022-03283-7

Excerpt:

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Funding

This work was funded by the National Natural Science Foundation of China (grant numbers 82073496 and 81673115), Huimin Project of Ministry of Science and Technology of China (grant number 2012GS610101), Department of Health of Shaanxi Province (grant number 2018D050), and International Cooperation Foundation of Shaanxi province (2020KW-057). CC was supported by NHMRC and The University of Queensland.

Author information

Affiliations

Contributions

Qun Chen designed the experiments, analyzed the data, and wrote the manuscript. Biqi He, Yanni Yang, and Siyuan Dong performed the experiments. Zhaoqiang Zhou and Jinhai Wang provided intellectual inputs. Zhao Xu interpreted the results and critically reviewed the manuscript. Chen Chen was involved in the result interpretation, manuscript writing, and reviewing and editing.

Corresponding author

Correspondence to Qun Chen.